Section 157.24. Testing for leakage or contamination of sealed sources.  


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  • (1) General requirements. A licensee or registrant in possession of any sealed source shall ensure that all of the following requirements are met:
    (a) Each sealed source, other than hydrogen-3, with a half-life of 30 days or more and in any form other than gas or seeds of iridium-192 encased in nylon ribbon, shall be tested for leakage or contamination as follows:
    1. Prior to initial use.
    2. Unless otherwise authorized by the department, the NRC or another agreement state, at intervals not to exceed 6 months, except that each source designed to emit alpha particles shall be tested at intervals not to exceed 3 months.
    3. At any time there is reason to suspect that a sealed source might have been damaged or might be leaking, it shall be tested for leakage before further use.
    4. In the absence of a certificate from a transferor indicating that a test for leakage has been made within 6 months prior to the transfer, the sealed source may not be put into use until tested and the results received.
    (b) Notwithstanding the provisions of par. (a) , sources not in use and identified as being in storage shall meet all the following conditions:
    1. Sources other than brachytherapy or teletherapy sources shall be tested for leakage at intervals not to exceed 5 years.
    2. Sources shall be tested for leakage and test results received prior any use or transfer, unless a test for leakage has been made within 6 months prior to the date of use or transfer.
    3. Sources in storage shall be inventoried at intervals not to exceed 6 months.
    (c) Tests for leakage for all sealed sources, except brachytherapy sources manufactured to contain radium, shall be capable of detecting the presence of 185 Bq (0.005 m Ci) of radioactive material on a test sample. Test samples shall be taken from the sealed source or from the surfaces of the container in which the sealed source is stored or mounted on which one might expect contamination to accumulate. For a sealed source contained in a device, test samples shall be obtained when the source is in the "off" position.
    (d) Tests for leakage for brachytherapy sources manufactured to contain radium shall be capable of detecting an absolute leakage rate of 37 Bq (0.001 m Ci) of radon-222 in a 24 hour period when the collection efficiency for radon-222 and its progeny has been determined with respect to collection method, volume and time.
    (e) Test samples shall be taken from the interior surfaces of the container in which sealed sources of radium are stored. The test shall be capable of detecting the presence of 185 Bq (0.005 m Ci) of a radium daughter that has a half-life greater than 4 days.
    (2) Exemptions. Notwithstanding the requirements in sub. (1) , any sealed source is exempt from tests for leakage when the sealed source contains 3.7 MBq (100 m Ci) or less of beta- or gamma-emitting material or 0.37 MBq (10 m Ci) or less of alpha-emitting material.
    (3) Authorization to conduct testing. Tests for leakage or contamination from sealed sources shall be performed by persons specifically authorized by the department, an agreement state, a licensing state or the NRC to perform the services.
    (4) Records. Records of test results for sealed sources shall be made under s. DHS 157.31 (4) .
    (5) Leakage criteria. Any of the following shall be considered evidence that a sealed source is leaking:
    (a) The presence of 185 Bq (0.005 m Ci) or more of removable contamination on any test sample.
    (b) Leakage of 37 Bq (0.001 m Ci) of radon-222 per 24 hours for sources manufactured to contain radium.
    (c) The presence of removable contamination resulting from the decay of 185 Bq (0.005 m Ci) or more of radium.
    (6) Action required due to a leaking source. A licensee or registrant shall immediately withdraw a leaking sealed source from use and shall take action to prevent the spread of contamination. The leaking sealed source shall be repaired or disposed of under the requirements of this chapter.
    (7) Reports. Reports of test results for leaking or contaminated sealed sources shall be prepared under s. DHS 157.32 (7) and retained for 3 years after disposal or repair of the source.